1. Field
Exemplary embodiments relate to a traffic sign recognizing apparatus and an operating method thereof, and more particularly, exemplary embodiments relate to a traffic sign recognizing apparatus, which is capable of improving performance of recognizing a traffic sign while a vehicle travels, and an operating method thereof.
2. Discussion of the Background
As information technology has rapidly developed, development of technology for various vehicle-related electronic devices related has also accelerated.
As various driver assistant technologies have been developed for notifying a driver of relevant information by analyzing an image photographed by a camera. Technology for preventing dangerous situations has been suggested, such as acceleration. Technology for supporting a driving path by recognizing road traffic signs and transmitting relevant information from the sign to a driver has also been suggested, in addition to technologies with functions such as lane departure alarms, vehicle collision alarms, and the like.
The technology of recognizing a traffic sign based on an image detects a sign area by using an algorithm recognizing a specific pattern within an image. Further, there is a technology, which has also been publicly known, for increasing a recognition rate for an object including a traffic sign by applying a tracking algorithm to data about a previously detected object and calculating similarity, in order to supplement a situation, in which a sign area is not detected or is erroneously detected according to a general condition of a road.
Most of the traffic signs have specific shapes and forms unlike other objects. For example, a shape of a traffic sign may include a specific circular form or a color feature with a red border, and a special feature of the traffic sign may be used as a comparison part for utilizing a tracking algorithm and detecting the traffic sign, so that it is possible to detect the traffic sign more easily compared to other objects.
In general, when a specific pattern related to a predetermined object is recognized within an image, a meaningful change is not generated in a subsequent frame for an already recognized object in most cases, so that it is not greatly difficult to apply the aforementioned tracking algorithm.
However, special case traffic signs, wherein a light emitting traffic sign includes a light source, such as an LED, is different from the aforementioned general case.
Particularly, when a light source is operated using a pulse width modulation method, it may be recognized by the naked eyes that the light source of the traffic sign is continuously turned on, but in actuality, the light source is repeatedly turned on and off over a predetermined cycle.
In this state, there is a considerably large possibility that an error can occur in analyzing an image generated by a camera and accurately recognizing such a traffic sign. A particular reason is that a shutter repeatedly receives and blocks light at a predesigned speed when the camera photographs a roadside or neighboring space of a vehicle. That is, a situation may occur wherein a partial area of a traffic sign will not be sufficiently shown in an image periodically captured by the camera, in contrast to the recognition by the naked eyes.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the inventive concept, and, therefore, it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.